1. Field of the Invention
This invention lies in the field of polyethylene pipe systems. More particularly, it is concerned with polyethylene pipe combinations where lengths of pipe have been joined by the butt fusion method, and in the course of joining have formed small beads on the outside and the inside surfaces of the pipe.
2. Description of the Prior Art
In the prior art, pipes have been joined by the fusion methods and little attention has been paid to the beads which have been formed. Some attention has of course been applied to the internal beads since they directly effect the flow of fluids through the pipe. Other apparatus has been designed for removing the inner bead formed by fusion joining of two pipes.
However, more recently, polyethylene pipes have been used to line larger pipes by insertion into metal pipes, which have, in the course of use, become corroded with pin hole leaks, etc. In order to insert the pipe more freely and to insert the largest possible size of pipe, it becomes important to remove the external bead so that it will slide past minor projections and crustations of rust and so on. There is also, of course, the aesthetic value of having a smooth contoured outer surface for the pipe. This invention is directed toward that end.